1. Field of the Invention
The invention relates to a fixing device for at least one operating element or fixing element suitable for application in sterile areas in surgical operations, which is largely freely positioned in three dimensions and supported for fixing, while the sterile area is separated from A non-sterile area substantially by a sheet-like covering means,
2. Description of the Prior Art
The performance of endoscopic operations, preferably on the human body, requires the physicians involved in the surgical operation to handle the endoscopic surgical cases precisely which are introduced into intracorporeal cavities through openings in the body. Particularly when surgical measures are taken through the abdominal wall several endoscopic instruments are required which must be operated independently of each other and which are to be handled each by different physicians involved in the operation. A viewing endoscope, which is normally connected to a video camera, is introduced into the body cavity for optically monitoring the operation; depending on the area of the operation this viewing endoscope is aligned with this area and appropriately positioned. Such optical monitoring of the surgical operations to be performed inside the body requires, however, a permanent tracking of the distal end of the video recording system having an endoscopic configuration, so that these instruments must be controlled and guided throughout the entire surgical operation. The surgical operations, which take a very long time, inevitably result in fatiguing of the physicians involved in the operation, particularly those who are merely dealing with the positioning and tracking of the respective instruments, specifically as these operations are monotonous activities which equally require, however, a maximum degree of concentration.
For relief of the operating staff from this strain, stand- or support-like arrangements have become known which permit the positioning of endoscopic instruments relative to a surgery area. These include support-like systems standing on the floor or provided for fastening on the operation table, which are equipped with a plurality of support arms whereof each is connected to joints, with the individual support joints being fixed by means of regulating screws or fixing mechanisms provided for rotational operation. Apart from the support systems suitable for manual operation, other support systems have become known, too, which are driven by an electric motor and which are positioned in three dimensions via an appropriate controller. All these known support systems are based on the common functional objective to position a surgical instrument, which is required for performing or monitoring an operation, near the intracorporeal operating area where the physician performs the surgical operation. To this end, the respective surgical operation is mounted on the distal terminal region of the support system, which must, on the one hand, be positioned with a minimum of obstacles in three dimensions, if possible, and, on the other hand, must be locked in a predetermined three-dimensional position whilst the locking must be easy to unlock again.
Apart from the different known support arrangements, which, are distinguished from each other by different structural mechanisms for fastening or locking, respectively, all known support arrangements are complex and expensive structures. Specifically, the purchasing costs play an important role in the selection of a handling system.
Another very important aspect in the structural design of the aforedescribed support or fixing devices is the possibility of sterilizing them, since they are envisaged for the application in the sterile section of operation rooms. Clamping or jointed connectors are tedious or complicated to sterilize due to their multi-part structure as a result of a great number of gaps and interstices. The support or fixing components are frequently surrounded by so-called sterile disposable sheathings which, however, render the operability of the individual support components substantially more difficult. Moreover, the necessity to use the sterile sheathings accounts for an additional cost factor, which is not small, particularly as at least one sheath is consumed for each operation.
The present invention improves a fixing device for at least one operating or fixing element suitable for application in a sterile area during operations, which is largely freely positioned in three dimensions and supported for fixing, in such a way that the expenditure for the fixing device to be used in the sterile area, which is incurred by sterilization in terms of operating technique and investment, is reduced to a minimum. Very expensive disposable materials such as those required in the known support or fixing devices should be entirely avoided. Apart therefrom, the fixing device permits an easy operability for the operating surgeon, in particular the complexity, which is required for the structure so that the fixing device with its support-like structure will be free three-dimensional positioning, and is as small and simple as possible. One essential aspect of the invention furthermore relates to the provision of a solution at the lowest costs possible, which mainly do not entail any operating and maintenance costs, or only slight costs, in everyday application.
The present invention takes the surgical operating towel or drape into consideration, which is used in all surgical operations and which separates the non-sterile area from the sterile area.
The surgical towels or drapes, which are mostly made of tissue (the explanation set forth hereinbelow applies on principle also to towels made of other materials or combinations of materials such as coated paper, synthetic towels, etc.), are mostly made of cotton or textile material dyed in green, and as such they are suitable for sterilization by appropriate washing processes and for repeated use. In surgical operations, sheet-like coverings of this kind are placed on the patient to be treated while an appropriate cut-out is left only on the body area where the surgical operation is to be performed. All the instruments and objects present above the sheet-like covering means are turned towards the operating surgeon and must be sterile whereas objects located underneath the sheet-like covering are required to satisfy only substantially lower demands in terms of sterility or no sterility requirements at all. The present invention makes use of this aspect.
In accordance with the present invention a fixing device for at least one operating element or fixing element suitable for application in the sterile area in surgical operations, which is largely free positioning in three dimensions and supported for being fixed, with the sterile area being separated from the non-sterile area substantially by means of a sheet-like covering, is improved by the provisions that a holding device is provided which is located in the non-sterile area and which comes into operative connection with the operating or fixing element via an effective area, while being at least separated by the covering, with the operative connection being based on magnetic forces.
The inventive fixing device is thus fundamentally composed of two component assemblies, i.e. those located in non-sterile condition underneath the covering and those located in the sterile area above the covering. The non-sterile components of the fixing means preferably comprise a fastening base which is configured either as a floor-mounted post or as clamping device for the releasable fixation on a fastening rail peripherally surrounding the operating table.
The holding device, which is preferably infinitely variably vertically adjustable about a vertical axis, is connected to the post or the clamping device, co-operating with the latter for forming a single unit. The holding device is configured as a permanent magnet in a simplest design, which comprises a plane, pan-shaped or concave-spherical effective area. Moreover, the option is provided that it is possible, in addition to the infinitely variable vertical adjustability of the holding device, to incline the holding device relative to a horizontally extending plane in such a way that the effective area of the holding device takes a position inclined relative to the horizontal, preferably at an inclination by 45xc2x0.
As an alternative to the use of a permanent magnet as a holding device, a solenoid is equally suitable which has magnetic forces determined as a function of the current supplied to the solenoid; as a result, the solenoid can be switched at least between an ON and an OFF state and moreover the solenoid can be continuously controlled between the ON and OFF states, which means that the magnetic field strength can be controlled to a maximum field strength level in an infinitely variable manner.
The non-sterile components of the fixing device are preferably disposed in the immediate vicinity of the operating table so that the operation drape for sterile covering of the patient lying on the operating table for treatment covers, at the same time, also the holding device with the corresponding fastening provisions. The operating drape, which presents a cut-out merely at the site of the surgical operation, has normally an integral design without any further discontinuities. Hence the operating drape ensures a largely reliable and large-area separation of the sterile area from the non-sterile area, a characteristic which the fixing device of the invention uses. On principle operating or fixing elements of any design, which present ferromagnetic properties in their turn, may be fastened on the operation towel resting on the effective area of the holding device, which elements may be fixed on the holding device in dependence on the intensity of the magnetic forces. It is thus fundamentally possible to place a supporting rod made of a ferromagnetic material on an effective area of the holding device having a planar configuration, merely separated by the covering, for three-dimensional fixing of the device. On the end of the supporting rod, which faces the operating area, connecting mechanisms known per se and having a joint-like configuration may be provided for fastening further operating elements having a support-like design, with the possibility of mounting an optical viewing endoscope on the distal terminal region of these further elements for monitoring a surgical operation. Like all other tools for application in the sterile section, the operating or fixing elements, respectively applied in the sterile areas, i.e. above the covering, are governed by the requirement of sterilizability which should be as easy and rapid as possible. This requirement, however, can be satisfied only in an unsatisfactory manner, if at all, with joint mechanisms of the known type which comprise two operating elements having a rod-shaped design for coupling to each other in such a way that they can be occupied relative to each other about all three-dimensional axes, largely without any impairment or interference, specifically as the structure of these known mechanisms is too complex and provided with a great number of gaps wherein the interstices cannot be completely sterilized.
To satisfy the requirement of a complete sterilization particularly suitable operating elements as joint connectors are provided with a pan-shaped joint structure of a concave design on one of their ends, which is made of a ferromagnetic material or comprises at least a ferromagnetic material. For reasons of complete sterilizability, the ferromagnetic material must have an annealing (Curie) temperature higher than 250xc2x0 C.
For coupling a second operating element, preferably of a rod-shaped design, this element presents a spherical counter-contour on one end thereof which is precisely fitted into the spherically designed pan contour of the first operating element. Depending on the selected material and the size of the joint form, the magnitude of the magnetic forces can be selectively set between the operating elements held together by magnetic forces, which ensure, on the one hand, a permanent jointing of both operating elements and permit, on the other hand, a rotational mobility through almost 360xc2x0 relative to each other, which the operating surgeon desires.
The foregoing statements referred to the simplest embodiment of a fixing device of the inventive configuration, i.e. the mere covering of the magnetic active surface of the holding by the covering configured as operation drape and an operating element disposed directly thereon, which is preferably configured in the manner of a supporting rod.
On account of the immediate contact with the covering, the operating element, which enters into a magnetic operative connection with the holding, is able to cause such a strong mechanical strain on the covering, which is preferably made of a textile tissue, due to relative movements occurring as a result of the operating surgeon""s manipulations for three-dimensional positioning of the endo-surgical instrument mounted on the distal end of the support system, such that wear of the covering cannot be precluded.
Moreover, with the aforementioned relative movements between the operating element and the active surface of the holding device, creases may be formed in the means which may lead to maladjustment or at least to an impeded free mobility of the support system. For avoidance of such creases, it is expedient to place an additional cap element on the holding device covered by the covering, which cap element covers at least the active surface of the holding device and is placed or plugged onto the holding device with the covering located immediately there above.
The cap element as such is provided with a cap cover which is preferably made of a ferromagnetic material and comprises a base plate into which a groove is machined which has an inside contour conformed to the outside contour of the operating element. In this manner it is possible, for instance, to insert a rod-shaped operating element into the groove in the ferromagnetic base plate of the cap element, for reasons of an improved fixing, where it is magnetically fixed. As a function of the magnetic forces which may be continuously controlled, for instance, when a solenoid is used, the operating element may be displaced along the longitudinal axis of the groove and rotated about the holding device, which presents preferably a circular outside periphery, together with the complete cap element. A non-magnetic cover plate is provided for an upper closure of the groove, which is designed to be open on one side within the base plate, which non-magnetic plate is placed on the base plate but does not enter itself into a magnetic interaction with the magnetic field caused by the holding device, so that the lines of the magnetic field will predominantly enter into the base plate and the operating element inserted into the base plate in a non-weakened form. It is ensured in this way that the major fraction of the magnetic flux serves to fix the operating element inserted into the base plate and is not oriented by fixing device components not participating in the fixing action, which would weaken the magnetic field.
To ensure a controlled rotational mobility of the cap element on the holding device covered by the covering without any risk of crease formation in the covering between the holding device and the cap element, pin-like projections are disposed in the area of the peripheral edge on the cap element, preferably at equal distances from each other, so that the pin-like projections will radically surround the holding device along a peripheral edge thereof when the cap element is placed onto the holding device. Due to the spaced arrangement of the pin-like projections on the cap element, the creases which may be formed during the placement of the cap element onto the sheet-like covering may largely freely unfold in the interstices between the pin-like projections. As a result, the sheet-like covering is actually stretched without any creases over the entire active surface of the holding device, which is covered by the cap element, and remains also free of creases even when the cap element is turned about the holding. The pin-like projections present a substantially round design in the manner of a finger so that the creases of the sheet-like covering means cannot be clamped between the projections and the holding but may rather be formed with a free fall between the pin-like projections. As the cap element with its base plate rests over a large area on the entire active surface of the holding element, while being separated by the sheet-like covering, the covering is subjected to a slight mechanical strain only even when the cap element is rotated about the holding so that wear of the covering can be largely precluded. Moreover, the sheet-like covering serves at the same time as an intermediate sliding layer between the base plate of the cap element and the active surface of the holding device so that, depending on the prevailing magnetic forces, the operating surgeon can rotate the cap element without any clamping. This free mobility is indispensable particularly for fine positioning of a video recording unit mounted on the distal end section of the operating elements having a support-like structure.
The fixing device of the invention serves not only for the aforedescribed releasable fixed connection of an operating element having a support-like structure on a holding disposed invariably relative to or on the operating table but can also be used for fastening or fixing the operating drape, for instance on the operating table or in the immediate vicinity thereof.
A holding device which has, for instance, a pan-shaped magnetic active surface may also serve as fixing element for the operating drape, which rests on the holding device and is fixed by means of a fixing element, which may be configured, for instance, as a sphere engaging with precise fit into the pan-shaped active surface of the holding device. The holding device is located in the non-sterile section and the fixing element, which has a spherical design, may be placed on the covering for engagement in the holding device from the sides of the sterile area. Fixing elements having such a configuration are furthermore easy to sterilize and suitable for manifold applications for fixing tasks in surgical operations.